Ref. 2016/17 Reviews: Frank D, DBA VHD 8x42 http://www.birdforum.net/showthread.php?t=317757
(also mentioned at http://www.birdforum.net/showthread.php?t=341911) Steve C, DBA HD 10x42 http://www.birdforum.net/showthread.php?t=317902
In Feb 2018, with thanks to the authors above, mine is the 10x42 version but I can only concur that Opticron's statement a is a pretty accurate representation: "Designed around and built for the professional and enthusiast looking for 8/10x42 quality but preferring the size, weight and feel of a smaller binocular, the DBA VHD offers an unrivaled combination of performance, comfort and ergonomics for under $1000. 100% made in Japan." and with those authors' (more reliable!) comments about the notable brightness, colour, contrast, and sharpness.
The armour is relatively hard, thin, and non-sticky but ahead of the objective lenses the rubber is extended by a thicker lip which adds depth to the recesses, as well as to protection. Between the hinges there are bare metal areas to make more room, each with an angle between two flats, further to assist the grip.
From Steve's remarks I gathered that eye relief might have presented a problem when wearing glasses but found that the quoted 17mm allowed the whole field to be included in the view. Initially there was some lumpiness at some positions of the focus wheel but this has largely gone away with use. The wheel has a fairly smooth grooved surface which falls readily to an index finger, not liable to slip because the action is lightly damped and not at all stiff. There is no free play or lateral movement.
Focussing range is 1.5 turns. This is a little faster than might be expected because infinity at is at 0.75 of a turn from the limit, out of the total 2.25 available. The central dioptre adjustment is quick and simple to set and the eyecups can't slip from intermediate or fully extended positions. This is because any pressure locks them in place, and they are reset by lifting them first.
From some illustrations I had thought the binoculars might have looked a bit rough and ready, but in the flesh they appear and feel dense, refined, and well finished, almost like metal. The composite straps carry smaller and neater quick links than those shown in Frank's Photos, and the details seem nicely done.
I got them for the open bridge design to help with steadiness, which it seems to do, and found them to be excellent all round.
Bright. Sharp for most of the field. Waterproof Porro. 10x
Closest focus is about 30ft. AFOV 5degr. poor lens caps.
The lens caps, rainguard, and strap are basic and the bag is just a cover but the finish and everything else gives an impression of quality. The weight seems less because they are large and have a comfortable shape with thumb depressions. There is plenty to hold on to, which makes the 10x magnification relatively easy to keep still.
The focus action is smooth and accurate. Unusually the focussing bridge itself is hidden inside the body and, although movements of the wheel require fairly firm pressure, the ribs on the wheel are sharp and prominent enough to make focussing easy. Using the natural and comfortable grip the large wheel falls straight to the middle fingers. There is no 'stiction' and the action is lighter than other waterproof porros (e.g. cf. Celestron Landscout and Nikon EX).
Dioptre adjustment has a clicking mechanism assisted by tabs, and the focus wheel slides forward with a click to lock it with a light but positive action. For subjects which are mainly in the middle and far distance this can usefully be set for best focus at infinity. The attachment thread for a tripod is directly above the centre of gravity.
The view was immediately pleasant, with natural colours. With the attention on the centre, the whole field seemed sharp and bright. Using a test chart, centre definition was only a little behind mid range roof prism 10x examples of Pentax ZD and Opticron DBA VHD, which understandably also appeared to have more saturated colour and stronger contrast. Away from the centre there was a little CA but pincushion distortion was notably less than usual: with a square frame occupying the whole field, all four lines were straight.
The August 2017 Albinos review https://www.allbinos.com/index.html?test=lornetki&test_l=324 says: "Blurring at the edge of the FOV: Blur occurs in a distance of 69% 4% from the field of view centre." In practice such blurring was not noticeable, although I suppose it contributed to Albinos' conclusion: "I would recommend the Pentax to those who care more about the usefulness of the instrument than its optical performance...."
Wearing glasses for distance, they worked for me with unextended click-up eyepiece covers. Close focus was as much as 30ft, with binocular overlap in evidence, and anyway the IPD would have needed adjustment for a closer view. The supplied individual objective caps were replaced with handier Vortex tethered rubber flip down covers.
I thought the sharpness, brightness, and colour were good for the purchase price of 155, and for me they were easy to use. Unless closer views are required I believe they offer an interesting large alternative.
Easy to hold still, Sharp image, wide field, 50mm for ease of use?
Stiff focussing & free play, closest focus is about 30ft
The Landscouts may be running out so I got both 10x50 and 7x35. I find longer reach better for the individual bird, but to me both versions seem nice and sharp for the price with their very wide angles and sweet spots, waterproofing, and no CA.
The downsides seem to be the minimum 30ft/12ft close focus and, both versions having the same bodies, variably heavy and lumpy focussing action and free play with the 10x50 so eventually they went back (but just firm and smooth with the 7x35 which I kept). The rainguard, strap, and bag are good but the individual plastic objective-cover inserts were too loose and easily fell out, so I got some rubbery caps with loops to replace them.
Handling is great. There is plenty to hold on to, and the weight definitely gives better steadiness at 10x compared to roofs. It's less of a problem at a distance too, and sitting down helps. Also maybe the 5mm exit pupil makes the eyepieces easier to line up than with the usual 4mm.
cf. Kowa YF30-6: Yosemite BX-1 has quick-clips on neck strap
cf. Kowa YF30-6: Yosemite BX-1 has loose, imprecise, eye cups
I could see no difference between the good central sharpness and view with Yosemite BX-1 and Kowa YF30-6, which was 25 more expensive when I purchased it in UK but could be worth it for the better eyecups.
However, and if weight is not so important, there are more substantial binoculars available at these prices.